Am Mo., 30. März 2020 um 19:23 Uhr schrieb Thiede, Christoph
<Christoph.Thiede at student.hpi.uni-potsdam.de>:
>
> I'm wondering how you can actually fill a book about this topic? Is that book about the actual implementation of a regex machine?

I wondered the same thing, so I googled this morning. You can look up
the table of contents online. One chapter indeed is about how to
implement regex machines (different approaches). But it is also about
using regular expressions in different programming languages,
optimization etc.